What foreign problems did Congress face during the 1780's?

The basic problem faced by Congress under the Articles of Confederation was that the US was poor and weak. Foreign governments therefore gave it no respect. We can see that most clearly in three ways.

First, the British kept forts on American territory. They used the forts as trading posts and to encourage Indians to attack Americans.

Second, the Spanish denied the Americans the use of the Mississippi. Spain closed the port of New Orleans to American trade. This meant Americans could not use the Mississippi as a way of getting goods to the ocean and around to the East Coast or Europe.

Finally, the Barbary Pirates attacked American shipping at will. The US could not prevent them or pay them off.

All of this shows that weakness was the major foreign policy problem for the new United States.